From bb41ef405f85175d1658cadd858796a02c0ea540 Mon Sep 17 00:00:00 2001
From: Andrea Sgattoni <andrea.sgattoni@rte-france.com>
Date: Mon, 20 Nov 2023 16:56:37 +0100
Subject: [PATCH] hard crash if one Xpress function not found

---
 ortools/base/dynamic_library.h | 14 +++-----------
 ortools/xpress/environment.cc  | 26 ++++++++++----------------
 2 files changed, 13 insertions(+), 27 deletions(-)

diff --git a/ortools/base/dynamic_library.h b/ortools/base/dynamic_library.h
index 2c36e185a29..7296785f60e 100644
--- a/ortools/base/dynamic_library.h
+++ b/ortools/base/dynamic_library.h
@@ -17,7 +17,6 @@
 #include <functional>
 #include <stdexcept>
 #include <string>
-#include <vector>
 
 #include "ortools/base/logging.h"
 
@@ -31,7 +30,6 @@
 #endif
 
 class DynamicLibrary {
-static constexpr size_t kMaxFunctionsNotFound = 10;
  public:
   DynamicLibrary() : library_handle_(nullptr) {}
 
@@ -59,10 +57,6 @@ static constexpr size_t kMaxFunctionsNotFound = 10;
 
   bool LibraryIsLoaded() const { return library_handle_ != nullptr; }
 
-  const std::vector<std::string>& FunctionsNotFound() const {
-      return functions_not_found_;
-  }
-
   template <typename T>
   std::function<T> GetFunction(const char* function_name) {
 #if defined(_MSC_VER) || defined(__MINGW32__) || defined(__MINGW64__)
@@ -73,10 +67,9 @@ static constexpr size_t kMaxFunctionsNotFound = 10;
     const void* function_address = dlsym(library_handle_, function_name);
 #endif  // MinGW.
 
-    // We don't really need the full list of missing functions,
-    // just a few are enough.
-    if (!function_address && functions_not_found_.size() < kMaxFunctionsNotFound)
-        functions_not_found_.push_back(function_name);
+    CHECK(function_address)
+        << "Error: could not find function " << std::string(function_name)
+        << " in " << library_name_;
 
     return TypeParser<T>::CreateFunction(function_address);
   }
@@ -100,7 +93,6 @@ static constexpr size_t kMaxFunctionsNotFound = 10;
  private:
   void* library_handle_ = nullptr;
   std::string library_name_;
-  std::vector<std::string> functions_not_found_;
 
   template <typename T>
   struct TypeParser {};
diff --git a/ortools/xpress/environment.cc b/ortools/xpress/environment.cc
index c7aad2d8b43..681840b72cd 100644
--- a/ortools/xpress/environment.cc
+++ b/ortools/xpress/environment.cc
@@ -95,7 +95,7 @@ std::function<int(XPRSprob prob, void (XPRS_CC *f_message)(XPRSprob cbprob, void
 std::function<int(XPRSprob prob, const char* flags)> XPRSlpoptimize = nullptr;
 std::function<int(XPRSprob prob, const char* flags)> XPRSmipoptimize = nullptr;
 
-absl::Status LoadXpressFunctions(DynamicLibrary* xpress_dynamic_library) {
+void LoadXpressFunctions(DynamicLibrary* xpress_dynamic_library) {
   // This was generated with the parse_header_xpress.py script.
   // See the comment at the top of the script.
 
@@ -158,15 +158,6 @@ absl::Status LoadXpressFunctions(DynamicLibrary* xpress_dynamic_library) {
   xpress_dynamic_library->GetFunction(&XPRSaddcbmessage, "XPRSaddcbmessage");
   xpress_dynamic_library->GetFunction(&XPRSlpoptimize, "XPRSlpoptimize");
   xpress_dynamic_library->GetFunction(&XPRSmipoptimize, "XPRSmipoptimize");
-
-
-  auto notFound = xpress_dynamic_library->FunctionsNotFound();
-  if (!notFound.empty()) {
-    return absl::NotFoundError(absl::StrCat("Could not find the following functions (list may not be exhaustive). [",
-                                            absl::StrJoin(notFound, "', '"),
-                                            "]. Please make sure that your XPRESS install is up-to-date (>= 9.0.0)."));
-  }
-  return absl::OkStatus();
 }
 
 void printXpressBanner(bool error) {
@@ -184,17 +175,18 @@ std::vector<std::string> XpressDynamicLibraryPotentialPaths() {
   std::vector<std::string> potential_paths;
 
   // Look for libraries pointed by XPRESSDIR first.
-  const char* xpress_home_from_env = getenv("XPRESSDIR");
-  if (xpress_home_from_env != nullptr) {
+  const char* xpressdir_from_env = getenv("XPRESSDIR");
+  if (xpressdir_from_env != nullptr) {
+    LOG(INFO) << "Environment variable XPRESSDIR = " << xpressdir_from_env;
 #if defined(_MSC_VER)  // Windows
     potential_paths.push_back(
-        absl::StrCat(xpress_home_from_env, "\\bin\\xprs.dll"));
+        absl::StrCat(xpressdir_from_env, "\\bin\\xprs.dll"));
 #elif defined(__APPLE__)  // OS X
     potential_paths.push_back(
-        absl::StrCat(xpress_home_from_env, "/lib/libxprs.dylib"));
+        absl::StrCat(xpressdir_from_env, "/lib/libxprs.dylib"));
 #elif defined(__GNUC__)   // Linux
     potential_paths.push_back(
-        absl::StrCat(xpress_home_from_env, "/lib/libxprs.so"));
+        absl::StrCat(xpressdir_from_env, "/lib/libxprs.so"));
 #else
     LOG(ERROR) << "OS Not recognized by xpress/environment.cc."
                << " You won't be able to use Xpress.";
@@ -244,7 +236,9 @@ absl::Status LoadXpressDynamicLibrary(std::string& xpresspath) {
     }
 
     if (xpress_library.LibraryIsLoaded()) {
-      xpress_load_status = LoadXpressFunctions(&xpress_library);
+      LOG(INFO) << "Loading all Xpress functions";
+      LoadXpressFunctions(&xpress_library);
+      xpress_load_status = absl::OkStatus();
     } else {
       xpress_load_status = absl::NotFoundError(
           absl::StrCat("Could not find the Xpress shared library. Looked in: [",